Air-heater.



E. B. FREEMAN.

AIR HEATER.

APPLICATION FILED rmm, 1909.

1,083,395, Patented Jan. 6,1914.

2 SHEETS-SHEET 1.

E. B. FREEMAN.

AIR HEATER.

APPLICATION FILED FEB.2, 1909.

Patented Jan. 1914.

2 SHEBTESHBET 2.

fill

STATES PATENT OFFICE.

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smaina'rnnl Patented Jan. 6, 1914.

To all whom it may concern:

Be it known that I, Eanss'r B. FnsmmN, citizen of the United States, residin at Dedham, in the county of Norfolk and tate of ltlassachusctts, have invented certaln new and useful Improvements in AIP-HGHtGIS; and- I do hereby declare the following to be a full," clear, and ,enactdescription of the invention, such as will enable others skilled in the art to which it appertains to nake and usethe same,

The invention relates to air heaters adapted to utilize waste heat infraismg the temperature of air to be used for ventilating,

heating, drying, or for any of the purposes for winch hot air is used in the arts.

The object of the invention 1s to provide an air'heater of this character having an'improved and novel constructionandarrangement' of pi es and connections. through which the a1r. to be heated-is circulated, whereby a large ,volume of a1r.- may be passed throughthe apparatus and etlic1ently heated, whereby the parts maybe convenicntlyassembled and installed, and whereby the apparatus maybe convemently kept in re air andgood working order.

0 these ends the invention comprises the features of construction and arrangement and the combinations of. arts hereinafter described and set forth in t 10 claims,

The various features of the invention will be readily understood from an mspe ct1on of the accompanying drawings, n wh1cl 1 Figure 1 is a perspective view filustratmg the general construction of an air heater cmbodyin the invention; Fig. 2 is a plan view part y in section; Fig. 3 1s a side elevation, parts of the wall boxes being broken away; and Fig. 4 is a vertical transverse section on line 4-4, Fig. 2.

In the construction illustrated in the drawin s, the pipes of the air heater through which t e air to be heated is passed are arranged vertically within a flue chamber 1, through which the hot ases ass from the fire boxes indicated at .to tie stack indicated at 8. A fan 4 ma be rovided for inducting a draft throng the us chamber if found desirable.

As shown, the heater comprises a plurality of sections, each section consisting of two'series of pipes 5 and 6 connected with headers at their' upper and lowerends. The lower headers 7, and; 8 for the two series of 3 application flied February 2, 1908. Serial No. 475,647.

pipes'connect with the pipes of each series at their lower ends, but do not afford communication between the two series of pi pus at this end of the section. The upper ends of the two series of pipes are connected by two upper: header sections 9 and 10 which form in efi'ect a single sectional header connecting the two series of )ipes, so that air passes through the header rorn one series of pipes into t e other. The two header sections 9 and 10 may be integrally connected to form a double header, but are preferably formed in two separate sections provided with abutting joint seats 11 and 12, through which the sections are united. The joint seats are preferably in the form of dan es surroundin the open ends of the header sections, an a suitable gasket packing is in terposed between the flanges to secure a tig it joint, the flanges bein bolted together as is usual with this form 0 joint.

While it is not essential to the broader features of the invention that the header for connecting the ends of the two series of pipes so that air is directed from one series of pipes into the other be arranged at the upper end of the section, this arrangement is preferable and forms a feature of the invention b which certain advantages are securcd. v this arrangement a strong and substantia sup ort is provided at the top of the heater for rmly su porting the mechanism necessarily used f r scra ing the circulating pipes. In case the header is formed in sections provided with joint seats, this arrangement results in the location of the oint between the header sections at the top of the heater where it is conveniently acces- Bible and where it is substantially out of the path of the hot (gases passing through the flue chamber, an is not, therefore, subject to deterioration and injury by the action of the hot gases.

The headers for connecting the lower ends of the ipes in each series are preferably of tuperc construction; that is to say, are so constructed that the cross sectional area of the passage for the air decreases from the open toward the closed end of the header so that a uniform distribution of the air to the tubes of the series connected to the header, and a substantially uniform velocity in the air passing through the header and tubes, is secured. For the same reasons, the header sections connecting the two series of pipes at "'erably :of a .1 vdouble-tapered ,construction';

that isto'sayjis soconstructedithat the-cross sectional area of the passage for the air decreasesyfronr the adjoining ends of the" header sections to their outer ends..

In order: thatthe air may be repeatedly subjected to the heatingaction of the hot gases passing through tie flue chamber, the heater may he provided with a plurality of sections connected iu series so that the air will pass through one section into a succeeding section, the number of sections connect-' ed in series so that-the air passes through one sect-ion after another, being varied in accordance with the size of the heater and the length of time it is desired that the air shall continue to be subjected to the heating action of the hot gases. In order that a lar e volume of air be handled, it is also desirab e that the heater sections be arranged in groups, and that the air, after bein passed through one roup of sections, be ehvered into a suceee ing group of sections connected in series with the first group, the number of groups connected in series depending upon the results which it is desired to secure and the conditions under which the apparatus is used. It is also preferred to arrange the sections transversely of the path of travel of the hot gases through the flue chamber and to provide wall boxes for connecting the sections in series, since with this construction and arrangement the joints in the devices for connecting the sections in series may be located outside of the walls of the flue chamber where they are convenient of access and where the pac 'ng in the joints is .not subjected to the action of the hotgases.

In the construction shown the lower headers 7 and 8 of the heater sections extend through the side walls of the flue chamber 1 and are flrmlv supported at their inner ends upon the wall 18. In order to enable a person to gain access to the pipes and devices within the interior of the flue chamber, the sections are preferably so arran ed with relation to the inner walls of the us chamber that passage ways 14 are provided between the walls and the circulating pipes, and the two series of pipes in each section are so arranged that a passage 15 is provided through the center of the sections. Deflecting plates 16 and 17 may be pivotally mounted within these passage ways to deflect the hot gases from the passage ways against the circulating pipes of the heater sections and maybe adjusted by turning them on their pivots or iinges. The ends of] the lower headers 7 and 8 which reject outside of the walls of the flue chamlger are provided with flanges 18 by which the headersare connected to the wall box sections 19.

'Thewall'box sections are so arranged and' connected that the heater sections are connected in groups, and the successive *roups .of sections are connected in series wit reach other, the air passing from one wall box section into the lower headers at one side of a vgroup of sections and passing from the ower box section which communicates with a wall box section connected to deliver the air'to the lower headers of the next succeedinggroup of sections. The wall boxes for delivering the air to the lower headers of the first group of sections is preferably of tapered construct-ion, so that a uniform dist-ribution of air to the sections and a uniform velocity in the air passing through the wall box is secured. For the same reason, the wall boxes for connecting two succeeding roups of sections are preferably of double-tapered construction, as indicated in the drawings.

A fan 20 is provided for forcing air through the wall boxes and heater sections, the air preferably entering the sections at the end of the flue chamber from which the hot gases escape, and being delivered from the sections at the end of the fine chamber where the gases are the hottest.

While it is preferred to employ the specific construction and arrangement of the parts shown and described, it will be understood thatthis specific construction and arrangementis not'essent-ial to the broader features of 'the'invention and maybe varied and modified without departing therefrom. 'Havingset forth-the nature and objectof the invention, and specifically described one form of apparatus in which it may be embodied, what I claim is 1. An air heater, having, in combination, a flue ch'ambena series of sections arranged transversely of the flue chamber and each consisting of two series of circulating pipes, lower headers connecting the pipes in each series and extending through the walls of the flue chamber, upper headers connecting the pipes in each series and having abutting i'oint seats, joint seats on the ends of the ower headers outside the flue chamber, and wall boxes outside the flue chamber provided with joint seats connectin the lower headers, substantially as descn ed.

2. An air heater, having, in combination, a flue chamber a series of sections arranged transversely oi the flue chamber and each consisting of two series of cireulatin r pipes, a header at one end of the section or each series of pipes and a header at the other end of the section connecting the two series to direct the air from one series into the other, a wall box outside the flue chamber connected by oint seats outside the flue chamber with a plurality of sections to direct air into a cup of sections, and a second wall box on side the flue chamber connected by joint seats outside the flue chamber with a group sections and a plurality of succeeding se tions to direct the air from one group of sections into a suoceedin group of sections, substantially as describe ,3. An air heater, having, in combination,

a flue chamber,"a plurality of sections arranged transversely of the chamber, each section consisting of two series of vertical circulating pipes, two uncommunicating lower headers extendin through the walls of the flue chamber, anfcommunicating upper headers connecting the two series of pipes, a wall box connected by joint seats outside theflue chamber with the lower headers of a plurality of sections at one side of the flue chamber, and a wall box connected by joint seats outside the flue chamber with the lower headers of a plurality of sections at the other side of the flue chamber and with the lower headers of a plurality of succeeding sections, substantially as dewalls of the flue chamber, upper oppositely tapered communicatin headers 9 and 10 connected with the series of pipes 5 and 6 respectivel and wall boxes connected with the ends 0 the lower headers outside the flue chamber, substantially as described.

5. An air heater, having, in combination a flue chamber, a series of heater sections arranged transverselyof the flue chamber and each consisting of two series of circulating pipes lower headers connecting the pipes in each series, upper headers connecting the pipes in each series, the heater sections being spaced from the walls of the flue chamber and the two series of circulating pipes of each section spaced from each other whereby a passage way is formed between each wall of the ue chamber and the heater sections and also between the pairs of series of circulating pipes, and adjustable deflecting plates mounted in the passage ways, substantially as described.

In testimon whereof I aifix my signature, in presence 0 two witnesses.

ERNEST B. FREEMAN. Witnesses:

IRA L. FISH,

N. D. MCPHAIL. 

